Steroid compounds and method of preparing the same



l atented Nov. 18, 1947 STEROID COMPOUNDS AND METHOD OF PREPARING THESAME Russell Earl Marker, Mexico City, Mexico, and Eugene Leroy Wittle,Detroit, Mich., assignors to Parke, Davis & Company, Detroit, Mich., a

corporation of Michigan No Drawing. Original application October 25,

1940, Serial No. 362,836. Divided and this application May 24, 1944,Serial No. 537,203

13 Claims. 1

This invention relates to the preparation of steroidal sex hormones fromsterols and bile acids.

This application is a division of our copending application, Serial No.362,836, filed October 25, 1940, and is directed more particularly tothe preparation of certain intermediate compounds which are convertibleinto sex hormones.

One object of this invention is to afford a process whereby compoundssimply convertible into sex hormones can be prepared from sterols orbile acids in improved yields.

Another object of this invention is to afford a simplified process forthe preparation of com-' pounds simply convertible into sex hormones.

Other objects will become apparent on perusal of this specification andthe appended claims.

We have developed a process in which the oxidation proceeds in goodyields to give intermediates which can be converted simply and in goodyields to the sex hormones.

Our process consists essentially in treating a eroid of the formula,

CH CH3 Where R is a member of the group consisting of hydrocarbonradicals and oxygenated hydrocarbon radicals, X is a halogen, and one ofY and Z is a member of the group consisting of hydrogen and halogen, theother being hydrogen, with an agent capable of oxidatively rupturingcarbonto-carbon bonds of the group R, treating the oxidation productshaving a shortened side-chain thus obtained to obtain the correspondingA unsaturated steroids, and treating these with an agent capable ofoxidizing a methylene group adjacent to a double bond, thus forming thecorresponding 3-keto M-unsaturated steroid-s having a shortenedside-chain.

In greater detail, our new process consists first in forming a 13 or n-un-saturated sterol or bile acid derivative. Because of theiravailability, we prefer to use as starting materials the naturallyoccurring sterols in which the side-chain R is a hydrocarbon radicalcontaining 8 to 10 carbon atoms. This side chain may be saturated, as incholesterol CaHrz or sitosterol 0101321, or it may be unsaturated as inergosterol Cal-I17. Sterols of this type are readily converted into thecorresponding B-desoxy compounds, i. e., into the A or n -unsaturatedhydrocarbons. Thus cholesterol may be distilled at atmospheric pressureto give M-cholestene, or it may be treated with phosphorouspentachloride or thionyl chloride to form cholesteryl chloride, and thelatter reduced, as for example, with sodium and amyl alcohol to yieldM-cholestene.

The A*- or A -unsaturated steroidal hydrocarbon used as a startingmaterial is first treated with halogen or hydrohalic acid to add theelements of these substances to the steroidal double bond. We prefer touse chlorine, bromine, hydrogen chloride or hydrogen bromide in thisstep. The compound thus obtained has a halogen atom attached to C andanother halogen atom or hydrogen atom, depending upon whether halogen orhydrohalic acid was added, is attached to the other carbon atom of theoriginal double bond. Thus when bromine is used to treat a A-unsaturated steroidal hydrocarbon, the intermediate compound obtainedhas the following formula,

CH3 CH3 where R is a member of the group consisting of hydrocarbonradicals and oxygenated hydrocarbon radicals.

When a A -unsaturated steroidal hydrocarbon is treated with bromine, theintermediate-compound obtained has the formula,

Br Br CH3 0 H3 o the resulting intermediate compound has the followingformula,

CH3 CH3 where R is a member of the group consisting of hydrocarbonradicals and oxy a hydrocarbon radicals.

The dihalide or hydrohalide addition product thus obtained is thenoxidized under conditions sufficiently vigorous to rupturecarbon-.toecarbon bonds. While a variety of agents may be employed forthis ,purpose,- we prefer to use chromic acid, permanganic acid or theirsaltsand we find it most convenient to conduct the oxidation in aceticacid below 100 C. and preferably at 35- 60 C.

After the oxidation has been completed, the products aresepara-ted so asto recover any starting'material and'then the oxidation'productconsisting of a mixture of steroids having shortened, oxygenatedside-chains is separated into its components according to severalpossible methods. It is convenient toremove the-elementsof halogen orhydrohalic acid ,at this ,point by treatment with a deha'logenati-ng "ordehydrohalogenating agent. Suitable dehalogenating agents include sodiumiodide, zinc and-aceticacid, metallic magnesium, and the-like, andsuitable dehydrohalogenating agents are basic substances such aspyridine, sodium acetate and other alkali metal salts of carboxylicacids, and the like.

If a Ar -unsaturated steroid has been used as a starting material or ifhydrogen halide was the agent added to the unsaturated steroid (either Aor A then the product formed after removal of the elements of halogen'orhydrohalic acid, as the case may be, is a M-unsaturated compound. If,however, the dihalide of a A -unsaturated steroid was the substanceoxidized, after removal of the elements of halogen the product obtainedis a A -unsaturated steroid and it is necessary at some point in theprocess to convert this into a N-unsaturated steroid. This is done byadding and then removing the elements of hydrohalic acid.

This shifting of the'doubiebond from A to A in the oxidation productsmaybe carried out at any stage after the unreacted startingmaterial hasbeen removed from the oxidation products but it must, of course, be donebefore the steroid is again oxidized to form the 3-keto steroid as setforth later in the specification.

The mixture of oxidation products is conveniently worked up by firstseparating the acidic and the non-acidic fractions according tomethodsWell known in the arts. Thenon-acidic fraction thus obtained is furthertreated to isolate the ketonic fraction and from the ketonic fractionthe l7-keto-androstane compound and the ZO-keto-pregnane compound areisolated. Then the 17-keto-androstane compound, if it still has thedouble bond in the A -position, may be converted into the correspondingA -andro stenone- 17. This is done as stated above by adding and thenremoving the elements of hydrohalic acid. For example, if hydrochloricacid is used, the

.sterone') The M-androstenone-l'l thus obtained may be oxidizedaccording to our new method to form A -androstendione-3,l7 and thelatter selectively reduced to form A -androstenol-1'7-one-3 (testo-Gtherwise the A -androstenone-17 may first be selectively reduced underconditions which .leave a double bond unaltered so as to formM-androstenol-ll, the hydroxyl group of the latter protected byconversion into a derivative hydrolyzable to regenerateM-androstenol-l'l and this derivative oxidized according .to our newmethod to form the corresponding derivative of A eandrostenol-l'l-one-3.

In either case the process involves the use of our new methodfor thepreparation of A -unsaturated 3-keto steroids from A -unsaturatedsteroids. This method consists in oxidizing to a ketone groupamethylenegroup adjacent to a double bond and this oxidation is effectedby first protecting any hydroxyl groups by converting these intoderivatives such as acetates, benzoates, trityl ethers or other groupshydrolyzable to give OH and oxidizing the derivative thus obtained withan agent capable of converting into a ketone group a methylene groupadjacent to a double bond. Such agents include chromic acid andpermanganic acid and their salts, as well as selenium dioxide. Theconditions of reaction depend on the particular oxidizing agentemployed, e. g., we prefer to use chromic acid in acetic acid at 30-60C.

The selective reduction of A -androstenone-1'7 may be accomplished witha wide variety of reducing agents. These include catalytic hydrogenationwith a Raney nickel catalyst, and the combination of an alkali oralkaline earth metal or aluminum and a substance having reactivehydrogen atoms. Reducing agents of the latter class include suchcombinations as sodium and ethyl alcohol, aluminum amalgam and aqueousammonium chloride, calcium and methanol, and the like. Instead of thesethe reduction may be conducted according to the method of Meerwein andPonndorff using, for example, ammonium iso- -propylate and'isopropylalcohol.

It will be appreciated that our invention also comprehends a new groupof intermediates for the preparation of sex hormones. This new group ofsubstances is representable by the general formula,

CH2 CH3 group of intermediate compounds represented by the followingformula,

Example 1 (a) In a 12 liter flask is placed 230 g. of A cholestenedibromide prepared, e. g., according to Mauthner, Monatsh, 27, 421(1906), and 500 cc. of carbon tetrachloride. When solution is complete,8 liters of glacial acetic acid are added and the solution warmed to 45C. with stirring. To this stirred solution at 4850 C. is added dropwisea stirred solution of 320 g. of chromic anhydride in 350 cc. of waterand 800 cc. of acetic acid over a period of four or five hours. Thesolution is stirred at 50 C. for six hours longer and then cooledwithcold water or ice to 30 C. Then ethyl alcohol (250 cc.) is addedslowly to this stirred solution over a period of about onehalf hour todestroy any excess chromic anhydride. The acetic acid is then removedunder reduced pressure until the volume of the solution has been reducedabout one-half. During the evaporation the temperature of the solutionis kept at 40-45 C. The solution is cooled slightly and the unchangeddibromide filtered off and dried. The filtrate is further concentratedunder reduced pressure at 40 C, until only a small quantity of aceticacid remains. This residue is diluted with 4 liters of water and 2.5liters of ether and stirred until all the material is in solution. Thewater layer is separated and extracted with 2.5 liters of ether. Thecombined ethereal extracts are washed well with 2 liters of water, 3v

liters of water containing 300 cc, of cone. hydrochloric acid, and thentwice with 1.5 liters of salt water, sufficient salt being added tocause rapid separation of the layers. The ethereal solutio then isevaporated to dryness, the last ether being taken 01f cautiously toavoid undue heat. The residue contains the dibromides of A-androstenone-l'l, A -pregnenone-20 and A -cholenic acid.

Instead of using A -cholestene dibromide in the above step, N-cholestene dichloride, A -sitostene dibromide, A -sitostene dichloride,or other dihalides of n -unsaturated hydrocarbons derived from sterolsmay be used instead.

(1)) One liter of acetic acid and 5 g. of zinc dust is added to thisresidue and the solution stirred vigorously and heated to 95 C. on thesteam bath. A further45 g. of zinc dust is added to this stirredsolution in small portions over a period of forty-five minutes. Then thesolution is filtered from the caked zinc and the latter washed well withacetic acid. The acetic acid filtrate is evaporated to dryness in vacuoon the steam bath and the residue dissolvedin 2 liters of ether. Theethereal solution is washed twice with water and the acid fraction isextracted with 5% sodium hydroxide solution until all acids are removed.

(0) The ethereal solution is evaporated to dryness and the residue steamdistilled to remove the volatile products. The residue is dissolved inether and the water layer removed. After evaporating the ether,theresidue is dissolved in 200 cc. of ethyl alcohol. Five grams ofsemicarbazide hydrochloride and 6 g. of sodium acetate are added and themixture refluxed on the steam bath for four hours, the alcohol beingallowed to evaporate to one-half volume. The solution is cooled anddiluted with 500 cc. of ether. After shaking the suspension for aboutone-half hour with cooling, 200 cc. of water is added. The solution isshaken and cooled in a salt-ice bath and then filtered with suction. TheWhite solid is washed well with water and ether. Then it is refluxedwith 50 cc. of alcohol for one hour, cooled, filtered, and air dried;yield 5 g. of white powdered semicarbazone, M. P, 285287 C. This is thesemicarbazone of M-androstenone-l'l.

(d) A solution of 6.7 g. of A -androstenone-17 semicarbazone, in 500 cc.of 95% ethyl alcohol, 35 cc. of concentrated sulphuric acid and 35 cc.of water is refluxed for two and one-half hours on the steam bath. Thesolution is diluted with water and the organic material extracted withether. The ethereal solution is washed well with water and sodiumbicarbonate solution and evaporated to dryness. The residue is purifiedby distillation at 80 C. in a molecular still and crystallization fromdilute alcohol toyield 3 g. of A androstenone-l'l', M. P, IOU- C. Onfurther purification the M. P. may be raised to 105-107 C.

(e) To a solution of 1.7 g. of A -androstenone-17 in 26 cc. of refluxingn-propyl alcohol is added 2.5 g. of sodium in small portions over aperiod of a half hour. Then the solution is poured into water and thewhite solid collected. This is crys tallized from methanol to yield 1.4.g. of A -androstenol-17, M, P. 163-165 C.

Three grams of M-androstenol-l'l is refluxed for one hour with 30 cc.acetic anhydride and then the solution is evaporated to dryness underreduced pressure. The residue is dissolved in hot methanol and allowedto crystallize. The A androstenol-17-acetate thus formed has M. P.133-135 C. Hydrolysis of this acetate, i. e., with alcoholic potassiumhydroxide, regenerates the original hydroxy compound, A -androstenol-17.

(f) A stream of dry hydrogen chloride is bubbled for several hoursthrough a solution of l g. of M-androstenol-l'l in about 20 cc. ofchloroform, cooled to 0 C. After the cold solution has stood for severalhours, it is carefully evaporated to dryness under reduced pressure on awater bath. The white solid hydrochloride remaining behind is A-androstenol-17 hydrochloride (5- chloro-androstanol-l'l) having thefollowing formula QHa CH3 7 anhydride for twohours. "FractionalcrystallizatiOn of the acetylated product yields a small amount of theless soluble A -androstenol-1'7 acetate, M. P. 133-135 C., and a largeramount of the more soluble M-androstenol-l'l-acetate, M. P. 97-100 C. Amixture of these two acetates gives a depression in melting point to72-82 C.

.A solution of 500 mg. of A -androstenol-1'I- acetate, M. P. 97-100 C.,in 25 cc. of methanol is refluxed for a half hour with a solution of 1g. of potassium hydroxide in cc. of 50% methanol. The solution isdiluted with water and extracted with ether. The ethereal solution iswashed with water and evaporated to dryness. The A -androstenol-l'? ispurified by crystallization from methanol, and then has M. P; 146-149 C.

To a solution of 200 mg. of A -androstenol-1'7 in 100 cc. of acetic acidis added 0.73 cc. of 1.05 molar bromine in acetic acid. This forms theintermediate compound 4,5-dibromo-androstanol-17. After a few minutes, asolution of 300 mg. of chromic anhydride in cc. of 90% acetic acid isadded with shaking. The solution is allowedto stand at room temperaturefor one hour, thus forming the intermediate compound4,5-dibromo-androstanone-l'l. It is then warmed with five grams of zincdust on the steam bath. The solution is filtered, poured into water andthe product extracted with ether. The ethereal solution is Washed wellwith water and dilute alkali and evaporated to dryness. The residue isdistilled in a molecular still under reduced pressure and thencrystallized from dilute methanol to give A -androstenone-17 of .M. P.78-80" C. This ketone gives a depression in meltin point to 60-65 C.when mixed with A -androstenone-1'7.

(g) To a solution of 2 g. of A -andr-ostenol-17- acetate in 75 cc. ofglacial aceticat 50 C. is added a solution of 2 g. of chromic anhydridein cc. of 90% acetic acid over a period of one hour. The solution ispoured into water and extracted with ether. The ethereal solution iswashed well with water and dilute sodium carbonate solution and thenevaporated to dryness. The resulting oil, which shows a high androgenicactivity, is treated in the known manner with Girards reagent T toseparate the ketonic fraction. The crude .ketone is hydrolyzed bywarming with alcoholic hydrochloric acid and then distilled in amolecular still at 0.01 mm. pressure. Crystallization of the product soobtained from etherpentane or dilute methanol gives testosterone, M. P.148-150 C., identical with the natural product.

What we claim as our inventionis:

1. Process which comprises dehydrohalogena ing a compound having theformula,

CH2 CH:

X thereby obtaining CH3 CH3 and X is halogen,

8. 2. Process which comprises treatin a compound having the formula,

CH3 CH with hydrogen halide thereb forming CH3 CH3 CH3 CH3 3. Processwhich comprises treating A' -androstenol-l'? with hydrogen chlorideforming 5 chloro androstanol l7, treating said product with fusedpotassium acetate and then with acetic anhydride thereby obtaining A-androstenol-l lacetate.

4. Process which comprises treating a 5-halo androstanol-17 compoundwith a dehydrohalogenating and an acylating agent thereby obtaining aM-androstenol-l'? acylate.

5. Process which comprises treating 5-ch1oroandrostanol-l'? with adehydrohalogenating and an acylating agent thereby obtaining A-androstenol-"l? acetate.

:6. Process which comprises treating A -androstenol-17 with hydrogenhalide thereby forming 5-halo androstanol-1'7 and treating the latterwith a dehydrohalogenating and an acylating agent thereby forming aM-androstenol-l'l acylate.

:7. .Process which comprises treating A -androstenol- 17 with hydrogenchloride thereby forming 5-chloro-androstenol-17 and treating the latterwith .a dehydroh'alogenating and an acetylating agent thereby obtainingA -androsteno1-17 acetate.

'8. The process which comprises treating A androstenol-l'? with hydrogenhalide and treating the product resulting "therefrom with adehydroha'logenating and an acylating agent thereby forming aM-androstenol-ll acylate.

9. The process which comprises treating A androstenol-l? with hydrogenhalide and treating the product resulting therefrom with adehydrohalogenating agent.

10. The process which comprises treating A andros'tenol-I'? withhydrogen chloride and treating the product resulting therefrom with adehydrohalogenating agent.

11. The process which comprises treating A androstenol- 17 with hydrogenhalide, treating the product resulting therefrom with adehydrohalogenating agent and then with an acylating agent therebyforming a M-androstenol-l'? acylate.

12. The process which comprises treating A androstenol-17 with hydrogenchloride, treating the product resulting therefrom with adehydrohalogenating agent and then with acetic anhydride therebyobtaining M-androstenol-l'? acetate. 10

13. The process which comprises treating A androstenol-l'l with hydrogenchloride, treating the product resulting therefrom with fused potassiumacetate and then with acetic anhydride thereby obtaining A-androsteno1-17 acetate.

RUSSELL EARL MARKER. EUGENE LEROY WIT'I'LE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS N me Date

